Clear findings: Sprinkler systems also save lives

Text: Frank Bieber, VdS Schadenverhütung GmbH

The National Fire Protection Association (NFPA) is an organization in the area of fire protection, fire prevention that develops globally recognized standards such as NFPA 13 for planning and installation of sprinkler systems. However, the NFPA also conducts research, partly through the Fire Protection Research Foundation. In April 2024, an NFPA research report entitled "US Experience with Sprinklers" was published.

The figures in the NFPA publication are estimates derived from the National Fire Incident Reporting System (NFIRS) of the US Fire Brigade (USFA) and the annual survey of US fire brigades conducted by the National Fire Protection Association (NFPA). Fires reported to federal, state, or plant fire brigades are not included in these estimates.

The NFPA survey of fire brigade experience provides estimates for the overall picture. NFIRS is a voluntary system through which participating fire departments provide detailed information about the fires they respond to. According to the fire brigade authority, over 22,000 fire brigades, fire departments, and fire services participate in data collection. Depending on the source, there are just under 30,000 fire brigades, fire departments, and fire services in the US, so participation in this data collection is very high.

To compensate for fires reported to local fire brigades but not recorded in NFIRS, scaling ratios are calculated and then applied to the NFIRS database using the following formula: NFPA Firefighting Survey projections / NFIRS total figures.

Fires in partially protected properties and cases where fires broke out in unsprinklered areas were ignored for the purposes of considering whether sprinkler protection was present and for triggered sprinklers.

From 2017 to 2021, local fire brigades, fire departments, and fire services responded to an average of approximately 53,000 fires per year in buildings where sprinkler systems were present, representing 11 percent of all building fires. This shows how widespread sprinkler systems shall be in the US.

These fires in sprinklered properties claimed an average of 36 civilian fatalities per year (1% of all fatalities in building fires), 1,002 civilian injuries (8%), and $1.2 billion in direct property damage (10%).

It should also be noted that the data was collected by fire departments and not by sprinkler system experts or specialists. This means that there is a certain degree of uncertainty in the evaluation of sprinkler systems.

Given these figures, it is of course very interesting to look at why the systems did not activate or were not effective. Let's first look at the systems that did not activate at all. Table 1 shows that 61% of the systems that did not activate were simply disabled and therefore could not be activated. The reasons for taking the systems out of service are not documented. However, it seems sensible to monitor the (operational) availability of the sprinkler systems electrically. This has been standard practice for systems complying with VdS regulations for years. Other regulations consider this function to be optional at most.

The next question is why systems triggered but were not effective. Table 2 shows that the largest proportion of systems were those in which the water did not reach the seat of fire. Again, there is no further detailed information available. However, it is plausible that there were spray obstructions that prevented the sprinklers from working. This shows that regular inspections of the systems are important. However, the inspection must not be limited to the pure system technology such as pumps or alarm valves. No, it is also crucial to check whether changes have been made in the extinguishing areas that affect the effectiveness of the sprinklers. New office fixtures or changes to room layouts can quickly lead to sprinkler no longer being effectively arranged. This check is an essential aspect of expert inspections by VdS.

In second place for lack of effectiveness is insufficient water supply. This can be due to faulty system technology, e.g., insufficient pressure in the water pipe network in the case of a direct connection or reduced pump capacity. Often, however, it is simply that the use no longer matches the original design of the firefighting system. In an apartment, the actual use will not change much.

But in a hotel, a chair storage room can become a mattress storage room full of foamed synthetic materials, and suddenly the design is no longer suitable. These changes can be particularly serious in industrial/logistics areas, for example, when metal or wooden storage containers are replaced with plastic ones. Here, too, it is crucial that the operator themselves, as well as the maintenance company and the expert(s), check whether the use still matches the design of the system.

Damaged components were responsible for the failure of sprinklers in only 6% of cases. This shows that sprinkler systems are very robust. The data on fires in residential buildings is particularly interesting [*2]. As already mentioned, sprinkler systems are uncommon in this type of building in Germany. However, in 8% of the residential fires evaluated, an automatic firefighting system was present. In 98% of cases, these were sprinkler systems (89% wet (pipe) systems, 9% dry (pipe) systems). The remaining 2% are recorded as "Others" and also include pre-action systems and water spray extinguishing systems.

Fires can spread quickly, especially in buildings where there are no requirements for the fire resistance of building components or at least fire-retardant doors. Figure 9 shows that a sprinkler system can increase the proportion of fires in which the fire does not leave the room where it started by up to 57 percentage points. This effect is particularly low at eight percentage points in the healthcare sector (including hospitals and nursing homes), but it should be noted here that room doors often have fire protection engineering requirements and that limiting the fire to one room can also lead to casualties.

In addition to the important protection of life and limb, sprinkler also protect real value. The study shows that property damage, loss of property is 66% lower in fires in places of assembly, 59% lower in healthcare facilities, and 69% lower in shops and offices. At first glance, it is surprising that no reduction in property damage was observed in production facilities and warehouses. However, it shall be taken into account that, on the one hand, sprinklers are increasingly being installed in buildings where there is a high fire risk or a high expectation of damage. Sprinkler systems are therefore not ineffective here, but buildings without sprinklers have simply not received protection because there was a low expectation of damage.

On the other hand, the statistics only refer to property damage, loss of property. For operators and insurers, however, the damage caused by business interruption is often much greater. The author is not aware of any reliable sources for the following statement, but it is assumed that one to two-thirds of companies are no longer operating on the market one year after a major fire. Even if property damage, loss of property is paid for by the insurer, competitors do not sit idly by and customers switch providers.

The NFPA study impressively shows that sprinkler systems rescue lives. In the US, where significantly more buildings are equipped with sprinklers than in Germany, the mortality rate in residential fires is almost 90% lower in buildings with sprinklers than in buildings without sprinklers. Firefighters are injured less often, property damage, loss of property is significantly reduced – and all because sprinklers contain fires at an early stage or even extinguish them completely.

Why do we ignore these clear facts in Germany? While structural fire protection traditionally dominates in this country, active fire protection is often neglected. Yet practical experience shows that sprinkler systems offer reliable protection – even in residential buildings, nursing homes, and hospitals, where people are particularly at risk.

It is high time to rethink! Germany needs to see a wider use of sprinkler systems – not only in industrial construction, but everywhere where people live and work. We shall learn from the findings of the NFPA and finally establish sprinkler systems as what they have been proven to be: lifesavers.

*1: DIN EN 1717 – Protection of drinking water against contamination in drinking water installations and general requirements for protective devices/security devices to prevent drinking water contamination by backflow; German version EN 1717:2000; Technical rule of the DVGW.

*2: The statistics refer to houses and apartments. Dormitories, barracks, assisted living facilities, nursing homes, etc. are not included here.